(a) Technical Field
The present invention relates to a system and method for controlling inter-vehicle distance using a side and rear sensor. More particularly, it relates to a system and method to for controlling an inter-vehicle distance, which can allow a subject vehicle to avoid a front end collision with a preceding vehicle by guiding driver's steering input in a safe direction.
(b) Background Art
Generally, inter-vehicle distance control refers to a technology for automatically controlling a power system and a brake system of a subject vehicle (i.e., vehicle equipped with an inter-vehicle distance controlling system) to measure a distance between the subject vehicle and a preceding vehicle and aid the driver in maintaining a safety distance from the preceding vehicle.
Inter-vehicle distance secures a safety distance from a preceding vehicle by reducing the speed of the subject vehicle through control of the power train system and the braking system when a distance from the preceding vehicle falls within a predetermined safety distance.
Typically, in a vehicle equipped with an inter-vehicle distance controlling system, when there is no preceding vehicle, a vehicle cruises at a speed set by a driver. On the other hand, when there is a preceding vehicle, the vehicle maintains the same speed as the preceding vehicle while maintaining the distance from the preceding vehicle, and when the preceding vehicle disappears, the vehicle is again accelerated to a set speed and cruises at a constant speed.
When a driver sets a speed, the inter-vehicle distance controlling system allows a vehicle to cruise at the set speed without additional driver manipulation. Accordingly, the inter-vehicle distance controlling system can significantly reduce the manipulation of an accelerator on expressways or car-only roads, and can reduce driver's fatigue during long-distance driving, thereby increasing the driving convenience.
In the inter-vehicle distance controlling system, a radar sensor is often used to obtain information on the presence or absence of a preceding vehicle, and a distance (relative distance) and a relative velocity between a subject vehicle and a preceding vehicle.
As examples of prior art related to an inter-vehicle distance controlling system, there are Korean Patent Nos. 10-1092721 and 10-0916259 and Korean Patent Application Publication Nos. 10-2010-0060535 and 10-2009-0062527 which are hereby incorporated by reference in their entirety.
Due to a limitation (i.e., deceleration: 0.2 g to 0.3 g, g: gravity acceleration) in the deceleration of a vehicle equipped with an inter-vehicle distance controlling system, in emergent situations such as cases where a preceding vehicle is rapidly decelerated, (e.g., when a vehicle of a side lane suddenly cuts in, etc.), the conventional inter-vehicle distance controlling systems are not sufficient to avoid a collision with the preceding car.
In such situations, a typical inter-vehicle distance controlling system generally warns a driver and automatically cancels its operation. In this case, the driver must quickly take over the vehicle and directly step on a brake pedal to control the speed of a vehicle or swerve the vehicle to avoid a collision. Since not all drivers have the same level of reflexes to such situations, the driving safety cannot always be ensured in the conventional systems.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.